| Details: |
The first examples of magnetism that we encounter involve examples con-
taining 3d transition metal atoms. The localized electrons associated with
the 3d orbitals retain a local magnetic moment when solids are formed, giving
rise to various types of magnetic ordering. There are few magnetic members
among the 4d and 5d oxides where even the formation of a magnetic moment
is difficult. It was therefore a surprise when magnetic ordering temperatures
of 1023 K and 800 K were observed in the 4d transition metal oxides SrTcO3
[1] and CaTcO3 [2], far higher than their 3d counterpart. In this talk I will
discuss our recent work[3] to understand this puzzling experimental observa-
tion.
1. E. E. Rodriguez, F. Poineau, A. Llobet, B. J. Kennedy, M. Avdeev, G. J.
Thorogood, M. L. Carter, R. Seshadri, D. J. Singh, and A. K. Cheetham,
Phys. Rev. Lett. 106, 067201 (2011).
2. M. Avdeev, G. J. Thorogood, M. L. Carter, B. J. Kennedy, J. Ting, D.
J. Singh, and K. S. Wallwork, J. Am. Chem. Soc. 133, 1654 (2011).
3. S. Middey, A.K. Nandy, S. Pandey, P. Mahadevan and D.D. Sarma,
Phys. Rev. B 86, 104406 (2012). |